3D domain swapping modulates the stability of members of an icosahedral virus group
3D domain swapping modulates the stability of members of an icosahedral virus group
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DOI：
10.1016/s0969-2126(00)00508-6
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发表时间：
2000-10-15
期刊：
影响因子：
5.7
通讯作者：
Lin, TW
中科院分区：
文献类型：
--
作者：
Qu, CX;Liljas, L;Lin, TW
背景：水稻黄斑驳病毒（RYMV）是导致许多非洲国家水稻减产的主要病原。RYMV属于sobemovirus属，具有二十面体衣壳和单链、正义RNA基因组。结果：通过X射线晶体衍射法确定了RYMV的结构，并将其分辨率提高到2.8埃。衣壳含有180个拷贝的外壳蛋白亚基，以T = 3二十面体对称排列。每个亚基采用双辊p型夹层折叠。RYMV的衣壳结构与其他sobemoviruses的衣壳结构相似。然而，当与这些病毒相比时，RYMV C亚基的PA臂（其是调节准等效亚基相互作用的分子开关）与2倍相关的β A臂交换到类似的非共价键合环境。这种相同的结构元素在对称轴上的交换被归类为3D域交换，并在整个二十面体表面晶格中产生长程相互作用。生化分析支持的概念，3D结构域交换增加了RYMV的稳定性。结论：RYMV蛋白质之间的准等价相互作用的β A臂，其功能作为一个分子开关的N-末端有序残基的调节。比较分析表明，这种分子开关也可以调节病毒衣壳的稳定性。
Background: Rice yellow mottle virus (RYMV) is a major pathogen that dramatically reduces rice production in many African countries. RYMV belongs to the genus sobemovirus, one group of plant viruses with icosahedral capsids and single-stranded, positive-sense RNA genomes.Results: The structure of RYMV was determined and refined to 2.8 Angstrom resolution by X-ray crystallography. The capsid contains 180 copies of the coat protein subunit arranged with T = 3 icosahedral symmetry. Each subunit adopts a jelly-roll p sandwich fold. The RYMV capsid structure is similar to those of other sobemoviruses. When compared with these viruses, however, the PA arm of the RYMV C subunit, which is a molecular switch that regulates quasi-equivalent subunit interactions, is swapped with the 2-fold-related betaA arm to a similar, noncovalent bonding environment. This exchange of identical structural elements across a symmetry axis is categorized as 3D domain swapping and produces long-range interactions throughout the icosahedral surface lattice. Biochemical analysis supports the notion that 3D domain swapping increases the stability of RYMV.Conclusions: The quasi-equivalent interactions between the RYMV proteins are regulated by the N-terminal ordered residues of the betaA arm, which functions as a molecular switch. Comparative analysis suggests that this molecular switch can also modulate the stability of the viral capsids.